which is why I hate her
Yup. I don't remember who it was, but someone here yesterday came up with something pretty cool, a way to keep Thanos relevant to the whole tihng, and it makes sense.
He asked how we think it would be if Ultron was powered by the power gem. And the gem just like, happened to be on Earth. Yes, this never happened in the comics, but he said to look at it like this, the power gem is red, Ultron's mouth and eyes glow red.
So if Hank happened to discover this gem at some point, as a source of literal power, he could use it to power ultron. So not only this a powerful robot, but he is empowered by the power gem.
I for one like this idea, because
1. It keeps Thanos relevant, and keeps him still behind the scenes,
2. It is perfect for his continuity, the after credit scene could be, after Ultron is defeated by the avengers, Thanos comes to earth, and takes the power gem out of Ultron's core.